Benzyl chrysanthemumates

ABSTRACT

ESTERS OF CERTAIN BENZYL COMPOUNDS AND CHRYSANTHEMUMIC ACID ARE USEFUL AS INSECTICIDES.

United States Patent 3,792,079 BENZYL CHRYSANTHEMUMATES Vincent T. DOrazio, Kenya, East Africa, assignor to S. C. Johnson & Son, Inc., Racine, Wis. No Drawing. Filed July 28, 1971, Ser. No. 167,037 Int. Cl. C07c 69/74 US. Cl. 260-468 H 8 Claims ABSTRACT OF THE DISCLOSURE Esters of certain benzyl compounds and chrysanthemumic acid are useful as insecticides.

This invention relates to benzyl chrysanthemumates. In one of its more specific aspects, this invention relates to insecticidally active esters of certain benzyl compounds and chrysanthemumic acid, which acid is also referred to as 2,2-dimethyl-3-(2-methylpropenyl) cyclopropanecarboxylic acid.

Among the most widely used insecticides today are the pyrethrins, the active principal of pyrethrum flowers (Chrysanthemum cinerariaefolium). Pyrethrins (which may be described as esters of chrysanthemumic acid) have a high order of insecticidal activity, a low mammalian toxicity, and a range of desirable biological properties including rapid knock-down effect. However, the relatively high cost and the uncertain supply (due to economic and political factors) of pyrethrins have encouraged attempts to prepare synthetic insecticides which retain the desirable properties of pyrethrins. As a result, much research effort has been directed toward preparing compounds which have a structural similarity to pyrethrins; that is, such compounds are esters of chrysanthemumic acid.

It is an object of this invention to provide new benzyl chrysanthemumates. It is a further object of this invention to provide insecticidally active esters of certain benzyl compounds and chrysanthemumic acid. It is a further object of this invention to provide an insecticidal composition comprising insecticidally active benzyl chrysanthemumates and a solvent therefor. It is a still further object of this invention to provide a process for killing insects by contacting said insects with insecticidally active benzyl chrysanthemumates. Other objects of this invention will appear herein.

These and other objects are attained through the practice of this invention, at least one embodiment of which comprises providing benzyl chrysanthemumates having the general structure:

wherein each R and R is hydrogen, alkyl having 1-6 carbon atoms, alkoxy having 2-6 carbon atoms, bromo, chloro, fluoro, trifluoromethyl, cyano, nitroor sulfoxy; and R is hydrogen, alkyl having 1-6 carbon atoms, alkoxy having 2-6 carbon atoms, bromo, chloro, fluoro, trifluoromethyl, cyano, nitro, sulfoxy, or SO R wherein R is alkyl having 1-6 carbon atoms, phenyl, pnitrophenyl, chlorophenyl, dichlorophenyl, or alkylphenyl, wherein the alkyl has l-6 carbon atoms; provided that when R is hydrogen or methyl, each R and R is alkyl having 2-6 carbon atoms, alkoxy having 2-6 carbon atoms, bromo, chloro, fluoro, trifluoromethyl, cyano, nitro, or sulfoxy.

Another embodiment of this invention provides an insecticidal composition comprising (A) an insecticidally effective amount of a benzyl chrysanthemumate having ice the above general-structure and (B) a solvent for the benzyl chrysanthemumate.

Another embodiment of this invention provides a process for killing insects, wherein said process comprises contacting said insects with an insecticidally efiective amount of a benzyl chrysanthemumate having the above general structure.

In the definition of the above general structure, the term alkyl having 1-6 carbon atoms includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, and n-hexyl; the term alkoxy having 2-6 carbon atoms includes ethoxy, propoxy, pentoxy, and hexoxy; and the term alkyl having 2-6 carbon atoms includes ethyl, n-propyl, isopropyl, n-butyl, isobutyl,secbutyl, t-butyl, n-pentyl, and n-hexyl.

Whenever used in this application, the term chrysanthemumic acid" will be understood to include the various isomers of such acid. An especially preferred isomer is d-trans chrysanthemumic acid.

The compounds of this invention are named as benzyl chrysanthemumates. for example:

(31% /CH; 01% o\ o=oH-o-o11-o-o-cHi--N0 3 CH3 is p-nitrobenzyl chrysanthemumate, and

CH: CH;

o=oHofi -oH-o-0-cH,- on

a coin.

is 2,6-diethoxybenzyl chrysanthemumate.

Specific examples of other benzyl chrysanthemumates encompassed by this invention include:

p-fluorobenzyl chrysanthemumate p-trifluoromethylbenzyl chrysanthemumate p-cyanobenzyl chrysanthemumate 2,6-dichlorobenzyl chrysanthemumate 2,6-dimethyl-4-nitrobenzyl chrysanthemumate 2,6-dichloro-4-nitrobenzyl chrysanthemumate 2,6-dichloro-4-nitrobenzyl chrysanthemumate (using the d-trans acid) 2,4,6-tribromobenzyl chrysanthemumate 2,4,6-tribromobenzyl chrysanthemumate (using the dtrans acid) The benzyl chrysanthemumates of this invention exhibit good insecticidal activity toward insects and low mammalian toxicity and may be prepared by well-known esterification reactions, including:

(1) the reaction of a chrysanthemumyl halide (e.g., chloride, bromide) and the benzyl alcohol corresponding to the desired benzyl chrysanthemumatefor example, pnitrobenzyl chrysanthemumate may be prepared by reacting chrysanthemumyl chloride and p-nitrobenzyl alcohol.

(2) the reaction of an alkyl (e.g., methyl, ethyl chrysanthemumate and the benzyl alcohol corresponding to the desired benzyl chrysanthemumatefor example, pnitrobenzyl chrysanthemumate may be prepared by reacting ethyl chrysanthemumate and p-nitrobenzyl alcohol.

-(3) the reaction of an alkali metal (e.g., sodium, potassium) chrysanthemumate and the benzyl halide (e.g., chloride, bromide) corresponding to the desired benzyl chrysanthemumatcfor example, p-nitrobenzyl chrysanthemumate may be prepared by reacting sodium chrysanthemumate and p-nitrobenzyl chloride.

, mumate may be prepared by reacting, in the presence of triethylamine, chrysanthemumic acid and p-nitrobenzyl chloride.

The details of the above esterification reactions are wellknown and need not be described herein.

An insecticidal composition is obtained when the composition contains from about .01 to about 20 percent, by weight, of a benzyl chrysanthemumate of this invention. A preferred amount is from about 0.1 to about 15 percent.

Minor amounts of other substances may be added to the insecticidal compositions of this invention in order to provide particular functional or esthetic effects. Examples of such substances are perfumes, corrosion inhibitors, buffering agents, wetting agents, ultraviolet radiation absorbers, fillers, flame retardants, antioxidants, emulsifiers, and disinfectants.

The insecticidal compositions of this invention may be formulated in a number of ways to permit convenient application by the user. For example, pressurized compositions may be formulated wherein the composition in the container is in the form of an oil-in-water emulsion, a water-in-oil emulsion, or a solution. Such pressurized compositions may be prepared to give space sprays or surface sprays. Pressurization can be accomplished with propellants known in the art, including liquifiable hydrocarbons (such as propane, butane, and isobntane), liquifiable fluorinated alkanes (such as dichlorodifl'uoroethane, difiuoroethane, and tetrafluoroethane) and compressible inert gases (such as nitrous oxide, nitrogen, and carbon dioxide).

Pressurized solvent compositions may be prepared by dissolving the benzyl chrysanthemumate in a suitable solvent (such as acetone, ethanol, naphtha, kerosene, or mineral spirits) and then pressurizing with one of the above propellants.

Pressurized oil-in-water compositions may be prepared by emulsifying the benzyl chrysanthemumate and any other hydrophobic components in water and then pressurizing with one of the above propellants.

These insecticidal compositions can also be formulated for use in hand sprayers, pump sprayers, foggers, and the like. These non-perssurized compositions can be in the form of oil-in-water emulsions, water-in-oil emulsions, or solutions. Except for the omission of the propellant, the non-pressurized compositions are prepared similarly to the pressurized compositions.

When preparing insecticidal compositions, one or more additional insecticides may be used in combination With the benzyl chrysanthemumates of this invention. Examples of such additional insecticides include pyrethrins, synthetic pyrethrins, and carbamates.

Examples of synthetic pyrethrins are 5-benzyl-3-fury1- methyl-d,l-trans-chrysanthemumate (available from S. B. Penick Division, Corn Products Co.) and the other insecticidal esters of chrysanthemumic acid described in US. Pat. 3,465,007; allethrin (available from McLaughlin Gormley King Company); phthalthrin (available from Sumitomo Chemical Company under the trademark Neopynamin); and Dimethrin (available from McLaughlin Gormley King Company). Allethrin is the common name for the d,l 2-allyl 4-hydroxy-3-methyl-2-cyclopenten-1- one ester of cisand trans-d,l-chrysanthemumic acid. Phthalthrin is the common name for N-(3,4,5,6-tetrahydrophthalimido)-methy1 chrysanthemumate. Dimethrin is 4 a trademark for the ester of 2,4-dimethylbenzyl alcohol and chrysanthemumic acid.

Examples of the carbamate insecticides are 2-isopropoxyphenyl-N-methylcarbamate (sold by Chemagro under the trademark Baygon) and the carbamates described in US. Pat. 3,362,871.

In addition, increase in insecticidal activity may be attained by combining the benzyl chrysanthemumates of this invention one or more synergists. Examples of preferred synergists include dipropargyl phenylphosphonate, safrole (4 propenyl 1,2-methylenedioxybenzene), dihydrosafrole (4 n propyl-1,Z-methylenedioxybenzene), piperonyl butoxide, and derivatives thereof.

Synergistic insecticidal compositions are obtained in accordance with this invention when the weight ratio of the insecticide portion to the synergist portion is from about 1:1 to about 1:10.

This invention will be further illustrated by the following examples of preferred embodiments. However, it will be understood that these examples are included for purposes of illustration and are not intended to limit the scope of this invention.

In the following examples, the term LD refers to that amount, expressed in micrograms per insect, required to kill 50 percent of the insects treated.

EXAMPLE 1 An insecticidal composition is prepared by dissolving 0.1 gram of p-fluorobenzyl chrysanthemumate in 10 ml. of ethanol. Bioassays that establish the female housefly mortalities are conducted by applying 0.5 microliters of the composition on the insects ventral abdomen. Each test is replicated twice with 25 female housefles that have been anesthetized with carbon dioxide. Mortality readings are recorded 24 hours after the initial treatment. By this procedure, a compound is considered insecticidal if the LD is 10 or less.

The LD of p-fluorobenzyl chrysanthemumate is 5.12.

EXAMPLE 2 The procedure of Example 1 is repeated except that pfluorobenzyl chrysanthemumate is replaced with other benzyl chrysanthemumates as indicated. The following results are obtained:

2 chloro 6 nitrobenzyl chrysanthemumate (using the d-trans acid) 6.69

2,4,6-tribromobenzyl chrysanthemumate .67 2,4,6-tribromobenzyl chrysanthemumate (using the d-trans acid) .30

Although this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of this invention as described hereinabove and as defined in the appended claims.

I claim:

1. A benzyl chrysanthemumate selected from the group consisting of 2,6-dichlorobenzyl chrysanthemumate 2,6-dimethyl-4-nitrobenzyl chrysanthemumate 2,6-dichloro-4-njtrobenzyl chrysanthemumate 5 the d-trans isomer of 2,6-dichloro-4-nitrobenzyl chrysanthemumate 4-nitro-6-chlorobenzyl chrysanthemumate 2,4,6-tribromobenzyl chrysanthemumate and the d-trans isomer of 2,4,6-tribromobenzyl chrysanthemumate. 2. As defined by claim 1., the compound 2,6-dichlorobenzyl chrysanthemumate.

3. As defined by claim 1, the compound 2,6-dimethyl-4- nitrobenzyl chrysanthemumate.

4. As defined by claim 1, the compound 2,6-dichloro-4- l0 nitrobenzyl chrysanthemumate.

5. As defined by claim 1, the compound the d-trans isomer of 2,6-dich1oro-4-nitrobenzyl chrysanthemumate.

6. As defined by claim 1, the compound 4-nitro-6-ch1orobenzyl chrysanthemumate.

7. As defined by claim 1, the compound 2,4,6-tribromobenzyl chrysanthemumate.

8. As defined by claim 1, the compound the d-trans isomer of 2,4,6-tribromobenzyl chrysanthemumate.

References Cited UNITED STATES PATENTS 3,358,011 12/1967 Elliot 260-468 3,393,064 7/ 1968 Richter 71-100 3,597,469 8/1971 Bradwell 260-468 FOREIGN PATENTS 40/ 1 1,499 6/ 1965 Japan 260-468 OTHER REFERENCES Elliot et aL, Nature, 207, 938 1965). Elliot et al., J. Sci. Food Agriculture, 18, 325 (1967).

LORRAINE A. WEINBERGER, Primary Examiner R. GERSTL, Assistant Examiner US. Cl. X.R.

260-456 R, 456 P, 465 D; 424-306 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 9 9 Dated February l2, l974 ;Inventor(s) Vincent T. D'Orazio It is certified that error appears in the above-idehtified patent and that said Letters Patent are hereby corrected as shown below:

Column l,- line 59, "nitro should be "nitro" Column 2, lines 19, 49 and 52 and Column 4, lines 55, 59 and 62,

"trans" should be italicized.

Column 2, line 26, "NO" should be "N0 Column 3, line 53, "n on-perssurized should be "non-pressurized" Column 3, line 64, "d, l-trans" should be italicized Column 3, line 72, "d, 1 should be italicized Column 3, line 73, "cis" and "trans -d, 1" should be italicized Column 4, line 9, "with" should be inserted after "invention" Column 4, line23, l 'LD50" should be "LD5 Columnl, line33, "housefles" should be "houseflies" Claim 1, lines 6 and 10, Claim 5, line 1, and Claim 8 line 1, "trans" should be italicized.

Signed and sealed this 17th day of September 1974.

(SEAL) Attest: I I MCCOY M. GIBSON JR'. c. MARSIIALL DANN I Attesting Officer Commissioner of Patents FORM PO-105O (10-69.)

USCOMM-DC scan-P69 u.s. GOVERNMENT PRINTING OFFICE: [969 0-118 134 

